package com.zxh.gulimall.product.service.impl;

import org.springframework.stereotype.Service;

import java.util.AbstractCollection;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.zxh.common.utils.PageUtils;
import com.zxh.common.utils.Query;

import com.zxh.gulimall.product.dao.CategoryDao;
import com.zxh.gulimall.product.entity.CategoryEntity;
import com.zxh.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {
        // 1、查出所有分类
        List<CategoryEntity> entities = baseMapper.selectList(null);

        // 2、组装成父子的树形结构
        // 2.1 找到所有的一级分类
        List<CategoryEntity> levelMenus = entities.stream().filter(categoryEntity -> categoryEntity.getParentCid() == 0)
                .map((menu)->{
                    // 设置一级分离的子分类
                    menu.setChildren(getChildren(menu,entities));
                    return menu;
                }).sorted((menu1,menu2)->{
                    // 排序
                    return (menu1.getSort() == null ? 0: menu1.getSort()) - (menu2.getSort() == null ? 0:menu2.getSort());
                }).collect(Collectors.toList());
        // 2.2 递归查找所有菜单的子菜单
        return levelMenus;
    }

    @Override
    public void removeMenuByIds(List<Long> catIds) {
        //TODO 1、检查当前删除的菜单，是否被别的地方引用
        baseMapper.deleteBatchIds(catIds);
    }

    //递归查找所有菜单的子菜单
    public List<CategoryEntity> getChildren(CategoryEntity root,List<CategoryEntity> all){
        List<CategoryEntity> children = all.stream()
                .filter(entity -> entity.getParentCid().equals(root.getCatId()))
                .map(categoryEntity -> {
                    //递归查找
                    categoryEntity.setChildren(getChildren(categoryEntity,all));
                    return categoryEntity;
                })
                .sorted((menu1,menu2)->{
                    return (menu1.getSort()==null?0:menu1.getSort())-(menu2.getSort()==null?0:menu2.getSort());
                }).collect(Collectors.toList());
        return children;
    }

}